Baird Creek: Degraded Wetlands

Degraded Wetlands

By Matthew Cole, Botanist
BCPF Board Member

The seventeen different plant communities present within the parkway provide a study in contrasts, between woods and fields or dry slopes and seeping wetlands, but also between natural splendor and unnatural blight.
In general, plant communities are hard for scientists to firmly define but relatively easy for the public to perceive. When you walk through a forest or a prairie or a river bottom, it is easy to notice that it isn’t all the same. The soil might change from rocky to wet, the slope could go from steep to flat, and the trees can change from sparse to dense or evergreen to deciduous. Scientists studying the patterns know that plants often group themselves in predictable ways. (But they also discover numerous mavericks, plants that grow wherever they please.) Hikers, nature-lovers and the general public notice these patterns as changes in color, temperature, comfort and aesthetic appeal. And everyone responds to these differences with changes in mood, thought, affection and appreciation.
Any plant community can be identified by looking at the dominant plants. They impart their own stamp and give the community its own pattern and value to the people who visit it. However there are some places that have begun to lose their distinctive-ness. Invasive species are good at penetrating existing plant communities. Some may appear as a smattering along roadsides and in disturbed areas. The worst ones do not need disturbance (mowing, fire, heavy traffic) to invade a natural community. And once the infestation reaches a critical mass, it may be impossible to return the plant community to what it was.

Reed Canary Grass in winter. Reed Canary Grass (Phalaris arundinacea) is one of the worst invaders. It forms dense stands that displace all other species, turning wetland communities to unnatural monocultures. The first plants spread by underground stems to form a clump, then a patch, then a stand. Since it spreads by expanding vegetatively, not by seeds, the genetic diversity can be close to zero. And the worst news is, it isn't the only invasive grass out there—it just currently has the largest footprint in the Baird Creek Greenway.

Several wetlands west of Highway 41 are already degraded. Once, these may have been sedge meadows, natural seeps or beautiful, green shelters for wild flowers and animal life. Now they are nearly impenetrable stands of a few invasive species that exploit the wet soil for themselves. These wetlands might still be considered valuable: they can prevent sediment from erosion from washing into Baird Creek, for example. But you could go to any disturbed wetland in Green Bay or Wisconsin—or any urban center and see the same thing! These western-most wetlands have lost all the distinctiveness and charm of the natural communities. They can't give us a sense of place, or recall the history of other residents and generations who enjoyed them.

Two responses are needed from you, the Foundation's membership. One is to recognize these degraded wetlands as communities that are less desirable than they might be. Unfortunately, in heavily infested sites, there is little long term success to report from anywhere in the country. Although the individual plants can be killed, re-sprouting and re-invasion are very common. So the second response is watch over our native communities. Notice and react when the community is first invaded. If you alert the Foundation to problems in the landscape, you can help to stop their spread before the damage is irreversible.

	Plant: Communities
	Degraded Wetlands By Matthew Cole, Botanist BCPF Board Member The seventeen different plant communities present within the parkway provide a study in contrasts, between woods and fields or dry slopes and seeping wetlands, but also between natural splendor and unnatural blight. In general, plant communities are hard for scientists to firmly define but relatively easy for the public to perceive. When you walk through a forest or a prairie or a river bottom, it is easy to notice that it isn’t all the same. The soil might change from rocky to wet, the slope could go from steep to flat, and the trees can change from sparse to dense or evergreen to deciduous. Scientists studying the patterns know that plants often group themselves in predictable ways. (But they also discover numerous mavericks, plants that grow wherever they please.) Hikers, nature-lovers and the general public notice these patterns as changes in color, temperature, comfort and aesthetic appeal. And everyone responds to these differences with changes in mood, thought, affection and appreciation. Any plant community can be identified by looking at the dominant plants. They impart their own stamp and give the community its own pattern and value to the people who visit it. However there are some places that have begun to lose their distinctive-ness. Invasive species are good at penetrating existing plant communities. Some may appear as a smattering along roadsides and in disturbed areas. The worst ones do not need disturbance (mowing, fire, heavy traffic) to invade a natural community. And once the infestation reaches a critical mass, it may be impossible to return the plant community to what it was. Reed Canary Grass (Phalaris arundinacea) is one of the worst invaders. It forms dense stands that displace all other species, turning wetland communities to unnatural monocultures. The first plants spread by underground stems to form a clump, then a patch, then a stand. Since it spreads by expanding vegetatively, not by seeds, the genetic diversity can be close to zero. And the worst news is, it isn't the only invasive grass out there—it just currently has the largest footprint in the Baird Creek Greenway. Several wetlands west of Highway 41 are already degraded. Once, these may have been sedge meadows, natural seeps or beautiful, green shelters for wild flowers and animal life. Now they are nearly impenetrable stands of a few invasive species that exploit the wet soil for themselves. These wetlands might still be considered valuable: they can prevent sediment from erosion from washing into Baird Creek, for example. But you could go to any disturbed wetland in Green Bay or Wisconsin—or any urban center and see the same thing! These western-most wetlands have lost all the distinctiveness and charm of the natural communities. They can't give us a sense of place, or recall the history of other residents and generations who enjoyed them. Two responses are needed from you, the Foundation's membership. One is to recognize these degraded wetlands as communities that are less desirable than they might be. Unfortunately, in heavily infested sites, there is little long term success to report from anywhere in the country. Although the individual plants can be killed, re-sprouting and re-invasion are very common. So the second response is watch over our native communities. Notice and react when the community is first invaded. If you alert the Foundation to problems in the landscape, you can help to stop their spread before the damage is irreversible.